They are both frameworks, they are both about governance, they both try to enable interoperability, they both define XML formats, they were both privately designed and they are both pushed by their authors (and supporters) towards standardization. To add to the confusion, Oracle is listed as a supporter of HP’s GIF and HP is listed as a supporter of Oracle’s IGF.

And yet they are very different.

GIF is an attempt to address SOA governance, which mostly relates to the lifecycle of services and their artifacts (like WSDL, XSD and policies). So you can track versions, deployment status, ownership, dependencies, etc. HP is making the specification available to all (here but you need to register) and has talked about submission to a standards body but as far as I know this hasn’t happened yet.

IGF is a set of specifications and APIs that pull access policy for identity related information out of the application logic and into well-understood XML declarations. With the goal of better controlling the flow of such information. The keystones are the CARML specification used to describe what identity related information an application needs and its counterpart the AAPML specification, used to describe the rules and constraints that an application puts on usage of the identity-related information it owns. The framework also defines relevant roles and service interfaces. Unlike GIF, which is still controlled by HP, IGF is now under the control of the Liberty Alliance Project. Oracle is just one participant (albeit a leading one).

Could they ever meet?

A Web service managed through a GIF-like SOA governance system could have policies related to accessing identity-related information, as addressed by IGF (and realized through CARML and AAPML elements). GIF doesn’t really care about the content of the policies. Studying the positions of the IGF and GIF specifications relative to WS-Policy would be a good way to concretely understand how they operate at a different level from one another. While there could theoretically be situations in which IGF and GIF are both involved, they do not do the same thing and have no interdependency whatsoever.

[UPDATED 2008/4/18: Phil Hunt (co-author of IGF) has a blog where he often writes about IGF. He also wrote a good overview of IGF and its applicability to governance and SOX-style compliance.]